1. Field
The present invention relates to the field of sample sensing.
2. Description of Related Art
Conventional sensing apparatuses use one or more optical sources to read samples. Biochip scanners, for example, use laser light to irradiate a chemical or biological sample, which, depending on material in the sample, responds by fluorescing. By detecting the light emitted by the sample, conventional apparatuses can identify specific materials in the sample, as well as the amount of those materials present. In one application, sensing apparatuses may be used, for example, to capture results from multiple reactions in real time by rapidly scanning the sample surface.
The samples may include, for example, a biochip. As appreciated by those of skill in the art, a biochip is a collection of test sites arranged on a solid substrate. These biochips allow scientists to monitor multiple chemical or biochemical reactions simultaneously, and have applications in genetics, toxicology, biochemical, protein, and other research areas related to chemistry and biochemistry. A biochip may contain thousands of individual test sites, each representing the outcome of an individual reaction.
Typically, conventional sensing apparatuses irradiate and monitor only one test site at time until each test site on the sample has been exposed. Conventional biochip scanners, for example, move either the sample or the body of the sensing apparatus in a linear or grid fashion, directing light to each individual test site on the sample. In this manner, the sensing apparatus scans each individual test site to determine whether it contains the material or materials to be sensed.
Conventional systems typically focus light emitted from the fluorescing sample onto a detector, such as a charge-coupled device or photomultiplier tube. A collection lens is typically placed so that its focal point coincides, or nearly coincides with a light-sensing surface of the detector. Such systems may also include a pin-hole lens to increase the signal-to-noise ration of the sensing system. The collection lens and/or pin-hole lens, however, increases manufacturing and assembly costs of the sensing system and adds to sensing system bulk and weight of the system.
Sensing and mapping materials on samples with multiple test sites in real-time requires sensing apparatuses capable of quickly directing and receiving light from distinct locations on the sample. Quickly collecting data from samples containing thousands of individual experimentation sites, like biochips, speeds research and saves laboratory resources. To effectively capture experimental results, therefore, it is desirable to provide sensing apparatuses and methods that hasten sample sensing.
Moreover, sensing apparatuses and methods capable of detecting materials on samples containing multiple test sites arranged in a non-rectilinear pattern create flexibility for users. Samples containing multiple test sites arranged in spirals, circles, or arcs, for example, provide enhanced sensing opportunities. While arranging test sites in a pattern other than a grid allows for a higher density of test sites on the sample, conventional sensing apparatuses are not configured to read samples laid out in this manner.
Additionally, it is desirable to create apparatuses and sensing methods that sense samples without moving the samples in rectilinear fashion, as done in conventional sensing apparatuses. Such apparatuses and methods can scan samples containing non-rectangular test sites.